The present invention relates to a cooler for hot smoke-laden gases which are to be cleaned by a pocket or tube filter situated in a downstream location, the cooler having a housing of rectangular horizontal cross-section through which the smoke-laden gas flows from top to bottom or from bottom to top and which is provided with cooling elements through which cold external air is conducted perpendicular to the direction of flow of the smoke-laden gas around the cooling elements.
To allow hot smoke-laden gases, e.g. from smelting furnaces, to be cleaned by means of pocket or tube filters, the temperature of the gases must be reduced to a level which can be tolerated by the particular filter material involved. There have generally been used for this purpose, so-called pocket coolers in which the open ends of the pockets are fitted over perforations in two opposing walls of the housing, the pockets, which are of the same height as the cooler housing, being fastened to the walls in a sealed fashion, e.g. by screws. The vertical surfaces of the pocket then provide a large area of heat-exchange surface in the enclosed space and they are freed from the dust which clings to them by swinging chains or cables.
The pockets of known coolers are expensive to manufacture and the thermal stresses which arise may cause them to bulge out or distend and thus hamper the cleaning by the chains. It is particularly difficult to seal such large cooling pockets satisfactorily and it can therefore always by expected that a fairly large amount of extraneous air will infiltrate into the smoke-laden gas. Apart from the high resistance offered to the flow of the cooling air through the pockets, it is an expensive and laborious business to exchange the large pockets when defective.
An object of the invention is to enable cooling elements in coolers for hot smoke-laden gases having a pocket or tube filter connected in a downstream location to be sealed satisfactorily and to be fitted and removed in a particularly simple fashion.
A further object is to reduce substantially the cost of manufacturing the cooling elements while lessening the risk of their bulging out and whilst ensuring an almost equally favourable utilisation of the available space as compared with cooling pockets.